Francium

Francium exists in minute quantities within the universe. As an alkali metal, francium shares similarities with elements like sodium and potassium but is the heaviest and least stable among them. Its isotopes are incredibly unstable, with the most stable isotope, francium-223, having a fleeting half-life of around 22 minutes. Due to its extreme scarcity and transitory nature, francium has negligible significance in astronomical bodies such as stars, planets, or celestial objects.